OSSC CHSL Syllabus 2026 & Exam Pattern: Subject-Wise Prelims & Mains Guide

Technical Paper (200 Marks)

• Computer Fundamentals: Evolution, characteristics, generations, and classification of computers.

• Hardware Components: Overview of Input/Output devices, CPU architecture, and Memory hierarchy (Primary, Secondary, Cache).

• Data Storage Solutions: Functionality of Hard disks, Pen drives, CD/DVD, and Memory cards.

• Software Categories: Understanding System software, Application software, and common Programming languages.

• Operating System Basics: Core concepts of Windows and DOS environments.

• MS Word: Advanced document creation, formatting, tables, mail merge, and proofing tools.

• MS Excel: Workbook management, data manipulation using formulas (SUM, AVG, COUNT, IF), charting, and data filtering.

• MS PowerPoint: Designing professional presentations, slide layouts, animations, and transitions.

• Internet Fundamentals: World Wide Web (WWW), browser utility, navigation, and search engine mechanics.

• Email Communication: Account management, drafting messages, and handling attachments.

• Networking Basics: Overview of LAN, MAN, WAN, network topologies, and IP addressing.

Unit IV: Digital Payments and E-Governance

• E-Governance initiatives and digital transformation programs in Odisha.

• Digital Finance: Understanding UPI, mobile wallets, and internet banking security.

Technical Paper (200 Marks)

• Fisheries: Definition, importance.
• Present status – Global, National, Odisha.
• Types of fisheries – Freshwater, Brackish water, Estuarine, Riverine, Reservoir, Lake.

• Freshwater resources – Rivers, reservoirs, lakes, ponds, tanks, canals, wetlands.
• Brackish water resources – Lagoons, estuaries, mudflats, backwaters.
• Inland fishery resources of Odisha.

• Economically important finfishes and shellfishes – Freshwater and brackish water.
• Identification, food and feeding habits, growth, reproduction, migration

Unit IV: Reservoir and Lake Fisheries

• Fisheries management in reservoirs and lakes.
• Stocking, conservation, and capture management.
• Floodplain wetlands – status, exploitation, management.
• Chilika Lake and Ansupa Lake – fisheries resources.

• Status, important species, and resource management.
• Fishing crafts and gears – Types, operation, restrictions.
• Fish Aggregating Devices (FADs).

• History of aquaculture – Global and national scenario.
• Principles and importance.
• Culture practices – Monoculture, composite culture, mixed culture, integrated aquaculture.
• Criteria for species selection.
• Sewage-fed fisheries, wastewater aquaculture.
• Culture methods – Extensive, semi-intensive, intensive.

• Types of fish farms – Freshwater, brackish water.
• Types of ponds – Nursery, rearing, grow-out.
• Layout, design, construction.
• Soil properties, sampling, seepage control.
• Hatchery, cage, and pen design.

• Nursery, rearing, grow-out pond preparation.
• Weed control, predatory and weed fish control.
• Liming, fertilization, bio-fertilizers.
• Stocking, feeding, health management, harvesting.

• Freshwater prawn culture – species, seed stocking, management.
• Brackish water aquaculture – finfish and shellfish species, seed collection, culture practices

• Ornamental fish culture – Indigenous and exotic species, rearing management.
• Catfish and air-breathing fish culture.
• Integrated aquaculture – Fish-cum-poultry, fish-cum-duck, fish-cum-cattle.

Unit I: Basic Chemistry Concepts

• Atomic mass, molecular mass, mole concept.
• Equivalent mass, percentage composition.
• Empirical and molecular formula.
• Concentration terms.

Unit II: Atomic Structure

• Atomic models – Rutherford, Bohr.
• Quantum numbers, electronic configuration.
• Aufbau principle, Pauli’s exclusion principle, Hund’s rule.

Unit III: Periodic Classification of Elements

• Modern periodic law, periodic trends.
• Atomic radius, ionization enthalpy, electron gain enthalpy, electronegativity.

Unit IV: Chemical Bonding

• Ionic and covalent bonds.
• VSEPR theory, hybridization.
• Molecular orbital theory (basic idea).

Unit V: States of Matter

• Gas laws, ideal gas equation.
• Kinetic theory, liquefaction of gases.

Unit VI: Thermodynamics

• Laws of thermodynamics, enthalpy, entropy.
• Gibbs free energy, spontaneity.

Unit VII: Equilibrium

• Chemical equilibrium, Le Chatelier’s principle.
• Ionic equilibrium, pH, buffer, and solubility product.

Unit VIII: Redox Reactions

• Study of oxidation numbers and methodology for balancing redox reactions.

Unit IX: Hydrogen

• Position in periodic table, isotopes, hydrides.
• Heavy water, hydrogen as fuel.

Unit X: s-Block Elements

• Detailed study of alkali and alkaline earth metals—properties and industrial applications.

• Groups 13 and 14: Chemical trends, properties, and practical uses.

Unit XII: Organic Chemistry Fundamentals

• IUPAC nomenclature, electronic effects.
• Reaction intermediates – carbocations, carbanions, free radicals.

Unit XIII: Hydrocarbons

• Alkanes, alkenes, alkynes – preparation, properties, reactions.
• Aromatic hydrocarbons – benzene, electrophilic substitution.

• Uniform and non-uniform motion, velocity, acceleration, graphs, circular motion

• Newton’s laws, inertia, momentum conservation.

• Universal law, free fall, mass, weight, pressure, buoyancy, Archimedes’ principle

• Work, energy forms, conservation of energy, and commercial units.

• Production, propagation, reflection, echo, ultrasound, sonar.

• Mirrors, lenses, mirror formula, lens formula, magnification, refractive index.

• Thermal equilibrium, laws of thermodynamics, isothermal and adiabatic processes.

• Current, circuit, Ohm’s law, resistance, series-parallel, heating effect, electric power.

• Magnetic field, Fleming’s rules, motor, generator, electromagnetic induction.

• Unit I: Matter – states, mixtures, solutions, colloids.
• Unit II: Atoms and Molecules – laws, atomic mass, mole concept.
• Unit III: Structure of Atom – models, isotopes, isobars.
• Unit IV: Chemical Reactions – types, oxidation-reduction.
• Unit V: Acids, Bases and Salts – properties, pH, common salts.
• Unit VI: Metals and Non-Metals – properties, reactivity, extraction.
• Unit VII: Carbon Compounds – bonding, nomenclature, ethanol, ethanoic acid, soaps.
• Unit VIII: Periodic Classification – Mendeleev, modern periodic table.

• Unit I: Biodiversity – five kingdom classification, vertebrates.
• Unit II: Cell – plasma membrane, nucleus, chromosome.
• Unit III: Tissues – plant and animal tissues.
• Unit IV: Nutrition – photosynthesis, human digestion.
• Unit V: Respiration – human respiratory system.
• Unit VI: Transportation – in plants and humans.
• Unit VII: Excretion – human excretory system.
• Unit VIII: Control and Coordination – nervous and chemical coordination.
• Unit IX: Reproduction – human reproductive system, STDs.
• Unit X: Heredity and Evolution – Mendel’s laws, Darwin’s theory.
• Unit XI: Energy Sources – renewable and non-renewable.
• Unit XII: Environment – ecosystem, food chain, nutrient cycle.
• Unit XIII: Conservation – forest, water, wildlife conservation.

• Introduction, generations, types.
• Input/Output devices, memory, storage.
• Computer languages.

• Practical proficiency in MS Word, MS Excel, and MS PowerPoint operations.

• Web browsing techniques, professional email management, and digital document handling.